5th wheel hitch

My FW0001 Holland/Binkley 5th wheel hitch setup on a 2001 Dodge Ram with Cummins turbodiesel.

When I decided that I was going to be hauling commercially, I knew I was going to have to go with a 5th wheel hitch. I had a B&W gooseneck hitch in the past and loved it, but gooseneck hitches are just NOT meant for stability. If you hook up a long trailer to a gooseneck ball and walk near the front of the trailer, you will feel how much movement it really has. The gooseneck ball has several degrees of movement in EVERY direction. Goosenecks were meant for oilfields and other uneven surfaces.

Look what happened to this guy who used a gooseneck hitch to haul a 2 car hauler... and this is with the width and stability of a dually. The trailer probably started to "go" given the side to side moving ability. Then it would've taken the truck with it, but the coupler broke. This might give you an idea why goosenecks need safety chains.

More pics of this accident are here.

OK, so now we have the goosenecks out of the way. I looked at EVERY single RV hitch out there. They are all junk for commercial hauling. Every single "heavy duty" RV hitch has lateral (side to side) movement, just like a gooseneck ball. Very few of them have "lock outs" to prevent this side to side movement, and the ones that do all have very low weight ratings. Why is this? If you look at an 18 wheeler, it has forward/aft movement and ABSOLUTELY NO lateral movement. The truck and trailer stay on the same lateral plane. This is what keeps the truck stable on the road and I wanted to have that too, especially since I am going to be pulling a 3 car trailer with a single rear wheel truck.

Even if the RV hitches didn't have side to side movement, very few of them are rated to the weights I want to carry. While my trailer weight will "only" be 19,000 lbs, I will have a very heavy pin, on purpose, to increase my control. Instead of 20% to 25% maximum for a RV, I expect to have 25% to 27%. 27% of 19,000 lbs is 5130#. I needed to find a hitch that would handle 5130# of hitch weight EASILY. OK so there are actually a few out there... Pullrite, Reese, etc. None of them promote commericial use. All of them are cheap and flimsy looking. All of them have lateral movement. And overpriced too. Would you trust your 5130# pin weight to these rails?

I honestly doubt if these rails would work on a truck without a bed (I had to pull my bed to meet certain state's length restrictions on Truck-trailer combinations).

Finally, I ordered a Holland/Binkley FW0001 miniature 5th wheel. It is rated to 8,000 lbs pin weight and 32,000 lbs towed weight. It has absolutely 0 degrees of side-to-side movement. I picked it up from TJ Trailers.com for $350 but they have since increased their price. Expect to pay about $400-420 plus shipping. The guys at TJ were very helpful. My hitch showed up a little "banged up" and I was concerned whether it had been used or not. They were willing to send me a new one no questions asked, but we ended up deciding it is just the nature of a very heavy item being moved around during shipping.

Now I had to figure out how to mount this sucker. I found out from a few people on DTR that our trucks are basically setup from the factory to accept a hitch like this:

There is an "indent" in the frame right above the axle that is about 10 or 11 inches wide and about 2.5 inches bottom to the top of the frame rail. An angle iron can be bolted here. I used 3/8" by 2.5" by 2.5". I had metalsdepot.com cut it to size for me since I do not have the tools to cut it. The price was $20 for the angle iron plus about $10 shipping. For bolts, I would suggest using at least 1/2" and Grade 8 bolts. These will shear at about 18,000 lbs each. See this page for more details about bolt strengths. For bolts, I would order them from McMaster Carr. They were much cheaper there than at my local hardware store.

You can see there is basically a "platform" for a plate of steel to sit on that is the width across the frame rails plus 3" on either side, by 10". Measure the width across the frame rails and add 6", then get a 3/4" plate of A36 steel that is 10" deep and the width that you have measured. Mine was 43" across. The cost for this was $90 plus about $30 shipping. The rust you see on the top of my frame rails is the remains of the hitch that the previous owner had welded to the top of the frame rails. This is NO GOOD. Don't do it. I had to slowly grind it off.

The 3/4" plate can then be bolted to the angle irons. With a 10" section you can probably fit 4 bolts. Since my 3/4" plate is only 8" deep, I only fit 3 bolts.

As for drilling advice, I would absolutely suggest that you get a strong drill and use it on LOW SPEED. Get the best "hard metal" drill bit that has a NO SLIP (triangle not round) chuck. Use lubrication meant for drilling, not just WD-40. I went through 3 $20 drill bits, but you could do this with just one. You might opt to just have a machine shop do it for you! (I probably would, in retrospect.).

This is where applications will be different. Since I don't have a bed and since I have a wedge trailer with an adjustable height coupler, I did not care about my hitch height. I just bolted my Binkley head right up to the main hitch plate by drilling 6 holes, 3 wide and 2 deep, into the Binkley's base plate and 6 holes into the 3/4" plate.

First thing I would say is, DO NOT DO THIS. The Binkley's base plate is meant to be welded. Have a professional truck or trailer shop weld it. What I have found, in bolting it, was that the bottom plate on the Binkley head was not completely straight. By bolting it down, I straigthened the plate out and now there is a very slight resistance on the pivot movement of the hitch head. I don't really think that this will effect the safety but I am not going to recommend it to others. It could be putting a small amount of stress on the huge welds that hold the head to the hitch plate.

Other things I would've done differently:
A) Get the absolute largest plate that you can get that will fit in the "indent." I probably could've squeezed another .5" or .75" on my side braces. So perhaps 10.5" on the side braces, then get a 10.5" top plate to match it.
B) Have a machine shop drill the holes. These holes took me way too long to do and some of them are not perfectly aligned. I would've gladly paid to have them done better.
C) Use larger bolts. It really can't hurt. I would use 7/16.
D) Use a thicker plate top plate. 1" instead of .75". Because why cheap out over $20 and a few pounds when everything is riding on this hitch.
E) Use thicker side braces. 1/2" instead of 3/8". Again because everything is riding on this hitch.

Here is the final product, painted and after first use. I recommend sanding and painting with Rust Bullet. My paint is coming off already.

If you are putting a gooseneck ball through this, I would suggest double plating the middle with another 3/4" thick plate maybe 8" by 12".

If you need to raise the hitch up to bed height, you might try using square hitch tubing 1/2" thick?.

Good luck and be safe!

Here is my car hauler hooked up to my 5th wheel hitch prior to dually conversion.